SoundSoftware Code Site

module CodeRay

module Scanners

  class C < Scanner

    include Streamable

    register_for :c

    file_extension 'c'

    RESERVED_WORDS = [

      'asm', 'break', 'case', 'continue', 'default', 'do',

      'else', 'enum', 'for', 'goto', 'if', 'return',

      'sizeof', 'struct', 'switch', 'typedef', 'union', 'while',

      'restrict',  # added in C99

    ]

    PREDEFINED_TYPES = [

      'int', 'long', 'short', 'char',

      'signed', 'unsigned', 'float', 'double',

      'bool', 'complex',  # added in C99

    ]

    PREDEFINED_CONSTANTS = [

      'EOF', 'NULL',

      'true', 'false',  # added in C99

    ]

    DIRECTIVES = [

      'auto', 'extern', 'register', 'static', 'void',

      'const', 'volatile',  # added in C89

      'inline',  # added in C99

    ]

    IDENT_KIND = WordList.new(:ident).

      add(RESERVED_WORDS, :reserved).

      add(PREDEFINED_TYPES, :pre_type).

      add(DIRECTIVES, :directive).

      add(PREDEFINED_CONSTANTS, :pre_constant)

    ESCAPE = / [rbfntv\n\\'"] | x[a-fA-F0-9]{1,2} | [0-7]{1,3} /x

    UNICODE_ESCAPE =  / u[a-fA-F0-9]{4} | U[a-fA-F0-9]{8} /x

    def scan_tokens tokens, options

      state = :initial

      label_expected = true

      case_expected = false

      label_expected_before_preproc_line = nil

      in_preproc_line = false

      until eos?

        kind = nil

        match = nil

        case state

        when :initial

          if match = scan(/ \s+ | \\\n /x)

            if in_preproc_line && match != "\\\n" && match.index(?\n)

              in_preproc_line = false

              label_expected = label_expected_before_preproc_line

            end

            tokens << [match, :space]

            next

          elsif scan(%r! // [^\n\\]* (?: \\. [^\n\\]* )* | /\* (?: .*? \*/ | .* ) !mx)

            kind = :comment

          elsif match = scan(/ \# \s* if \s* 0 /x)

            match << scan_until(/ ^\# (?:elif|else|endif) .*? $ | \z /xm) unless eos?

            kind = :comment

          elsif match = scan(/ [-+*=<>?:;,!&^|()\[\]{}~%]+ | \/=? | \.(?!\d) /x)

            label_expected = match =~ /[;\{\}]/

            if case_expected

              label_expected = true if match == ':'

              case_expected = false

            end

            kind = :operator

          elsif match = scan(/ [A-Za-z_][A-Za-z_0-9]* /x)

            kind = IDENT_KIND[match]

            if kind == :ident && label_expected && !in_preproc_line && scan(/:(?!:)/)

              kind = :label

              match << matched

            else

              label_expected = false

              if kind == :reserved

                case match

                when 'case', 'default'

                  case_expected = true

                end

              end

            end

          elsif scan(/\$/)

            kind = :ident

          elsif match = scan(/L?"/)

            tokens << [:open, :string]

            if match[0] == ?L

              tokens << ['L', :modifier]

              match = '"'

            end

            state = :string

            kind = :delimiter

          elsif scan(/#[ \t]*(\w*)/)

            kind = :preprocessor

            in_preproc_line = true

            label_expected_before_preproc_line = label_expected

            state = :include_expected if self[1] == 'include'

          elsif scan(/ L?' (?: [^\'\n\\] | \\ #{ESCAPE} )? '? /ox)

            label_expected = false

            kind = :char

          elsif scan(/0[xX][0-9A-Fa-f]+/)

            label_expected = false

            kind = :hex

          elsif scan(/(?:0[0-7]+)(?![89.eEfF])/)

            label_expected = false

            kind = :oct

          elsif scan(/(?:\d+)(?![.eEfF])L?L?/)

            label_expected = false

            kind = :integer

          elsif scan(/\d[fF]?|\d*\.\d+(?:[eE][+-]?\d+)?[fF]?|\d+[eE][+-]?\d+[fF]?/)

            label_expected = false

            kind = :float

          else

            getch

            kind = :error

          end

        when :string

          if scan(/[^\\\n"]+/)

            kind = :content

          elsif scan(/"/)

            tokens << ['"', :delimiter]

            tokens << [:close, :string]

            state = :initial

            label_expected = false

            next

          elsif scan(/ \\ (?: #{ESCAPE} | #{UNICODE_ESCAPE} ) /mox)

            kind = :char

          elsif scan(/ \\ | $ /x)

            tokens << [:close, :string]

            kind = :error

            state = :initial

            label_expected = false

          else

            raise_inspect "else case \" reached; %p not handled." % peek(1), tokens

          end

        when :include_expected

          if scan(/<[^>\n]+>?|"[^"\n\\]*(?:\\.[^"\n\\]*)*"?/)

            kind = :include

            state = :initial

          elsif match = scan(/\s+/)

            kind = :space

            state = :initial if match.index ?\n

          else

            state = :initial

            next

          end

        else

          raise_inspect 'Unknown state', tokens

        end

        match ||= matched

        if $CODERAY_DEBUG and not kind

          raise_inspect 'Error token %p in line %d' %

            [[match, kind], line], tokens

        end

        raise_inspect 'Empty token', tokens unless match

        tokens << [match, kind]

      end

      if state == :string

        tokens << [:close, :string]

      end

      tokens

    end

  end

end

end